1  package main
 2  
 3  import (
 4  	"strconv"
 5  )
 6  
 7  func formatFloat(f float64) string {
 8  	if f == float64(int64(f)) {
 9  		return strconv.FormatInt(int64(f), 10)
10  	}
11  	return strconv.FormatFloat(f, 'f', -1, 64)
12  }
13  
14  func Sqrt(x float64) float64 {
15  	if x < 0 {
16  		return 0
17  	}
18  	if x == 0 {
19  		return 0
20  	}
21  
22  	z := x
23  	for range 10 {
24  		z = z - (z*z-x)/(2*z)
25  	}
26  	return z
27  }